ALSA: hda - Make common input-jack helper functions

Since multiple codec drivers already use the input-jack stuff, let's
make common helper functions to reduce the duplicated codes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index fdf8d44..e46d542 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -866,6 +866,11 @@
 	/* codec-specific additional proc output */
 	void (*proc_widget_hook)(struct snd_info_buffer *buffer,
 				 struct hda_codec *codec, hda_nid_t nid);
+
+#ifdef CONFIG_SND_HDA_INPUT_JACK
+	/* jack detection */
+	struct snd_array jacks;
+#endif
 };
 
 /* direction */